diff --git a/contrib/gdb.py b/contrib/gdb.py
index 34bbb0ec..4c41edcc 100644
--- a/contrib/gdb.py
+++ b/contrib/gdb.py
@@ -203,7 +203,7 @@ class List234(gdb.Function):
 
     Arguments are a tree234, and optionally a value type. If no value
     type is given, the result is a list of the raw void * pointers
-    stored in the tree. Othewise, each one is cast to a pointer to the
+    stored in the tree. Otherwise, each one is cast to a pointer to the
     value type and dereferenced.
 
     Due to limitations of GDB's convenience function syntax, the value
diff --git a/crypto/argon2.c b/crypto/argon2.c
index 25385d7e..99bcfa17 100644
--- a/crypto/argon2.c
+++ b/crypto/argon2.c
@@ -266,7 +266,7 @@ static void argon2_internal(uint32_t p, uint32_t T, uint32_t m, uint32_t t,
      * that in the initial slice on the first pass, we've already written
      * values into the first two columns during the initial setup above. So
      * 'jstart' indicates the starting index in each segment we process; it
-     * starts off as 2 so that we don't overwrite the inital setup, and then
+     * starts off as 2 so that we don't overwrite the initial setup, and then
      * after the first slice is done, we set it to 0, and it stays there.
      *
      * d_mode indicates whether we're being data-dependent (true) or
diff --git a/crypto/mpint.c b/crypto/mpint.c
index fba9431d..544a18b5 100644
--- a/crypto/mpint.c
+++ b/crypto/mpint.c
@@ -1544,7 +1544,7 @@ mp_int *monty_export(MontyContext *mc, mp_int *x)
 mp_int *monty_pow(MontyContext *mc, mp_int *base, mp_int *exponent)
 {
     /*
-     * Modular exponentation is done from the top down, using a
+     * Modular exponentiation is done from the top down, using a
      * fixed-window technique.
      *
      * We have a table storing every power of the base from base^0 up
diff --git a/doc/config.but b/doc/config.but
index b5ad41d0..16cf8560 100644
--- a/doc/config.but
+++ b/doc/config.but
@@ -614,7 +614,7 @@ This option affects the arrow keys, if you press one with any of the
 modifier keys Shift, Ctrl or Alt held down.
 
 \b In the default mode, labelled \c{Ctrl toggles app mode}, the Ctrl
-key toggles between the default arrow-key sequnces like \c{ESC [A} and
+key toggles between the default arrow-key sequences like \c{ESC [A} and
 \c{ESC [B}, and the sequences Digital's terminals generate in
 \q{application cursor keys} mode, i.e. \c{ESC O A} and so on. Shift
 and Alt have no effect.
@@ -1369,7 +1369,7 @@ which one of the options is \q{Paste}). (This context menu is always
 available by holding down Ctrl and right-clicking, regardless of the
 setting of this option.)
 
-(When PuTTY iself is running on Unix, it follows the X Window System
+(When PuTTY itself is running on Unix, it follows the X Window System
 convention.)
 
 \S{config-mouseshift} \q{Shift overrides application's use of mouse}
diff --git a/ssh/sftp.h b/ssh/sftp.h
index 5835c16b..fb7d3267 100644
--- a/ssh/sftp.h
+++ b/ssh/sftp.h
@@ -327,7 +327,7 @@ struct SftpServerVtable {
     /*
      * Handle actual filesystem requests.
      *
-     * Each of these functions replies by calling an appropiate
+     * Each of these functions replies by calling an appropriate
      * sftp_reply_foo() function on the given reply packet.
      */
 
diff --git a/ssh/transport2.c b/ssh/transport2.c
index b4261562..2f9b02af 100644
--- a/ssh/transport2.c
+++ b/ssh/transport2.c
@@ -1922,7 +1922,7 @@ static void ssh2_transport_gss_update(struct ssh2_transport_state *s,
     s->gss_status |= GSS_KEX_CAPABLE;
 
     /*
-     * When rekeying to cascade, avoding doing this too close to the
+     * When rekeying to cascade, avoid doing this too close to the
      * context expiration time, since the key exchange might fail.
      */
     if (s->gss_ctxt_lifetime < MIN_CTXT_LIFETIME)
diff --git a/unix/window.c b/unix/window.c
index 93281429..5475fe9c 100644
--- a/unix/window.c
+++ b/unix/window.c
@@ -3194,7 +3194,7 @@ static void selection_received(GtkWidget *widget, GtkSelectionData *seldata,
         text = retrieve_cutbuffer(inst, &length);
         if (length == 0)
             return;
-        /* Xterm is rumoured to expect Latin-1, though I havn't checked the
+        /* Xterm is rumoured to expect Latin-1, though I haven't checked the
          * source, so use that as a de-facto standard. */
         charset = CS_ISO8859_1;
         free_required = true;
diff --git a/utils/tree234.c b/utils/tree234.c
index f9104158..83683f13 100644
--- a/utils/tree234.c
+++ b/utils/tree234.c
@@ -615,7 +615,7 @@ void search234_start(search234_state *state, tree234 *t)
 {
     state->_node = t->root;
     state->_base = 0; /* index of first element in this node's subtree */
-    state->_last = -1; /* indicate that this node is not previously visted */
+    state->_last = -1; /* indicate that this node is not previously visited */
     search234_step(state, 0);
 }
 void search234_step(search234_state *state, int direction)
diff --git a/windows/jump-list.c b/windows/jump-list.c
index 0aacee8f..39de1e00 100644
--- a/windows/jump-list.c
+++ b/windows/jump-list.c
@@ -12,7 +12,7 @@
  *
  * Since the jumplist is write-only: it can only be replaced and the
  * current list cannot be read, we must maintain the contents of the
- * list persistantly in the registry. The file winstore.h contains
+ * list persistently in the registry. The file winstore.h contains
  * functions to directly manipulate these registry entries. This file
  * contains higher level functions to manipulate the jumplist.
  */
diff --git a/windows/window.c b/windows/window.c
index 4d61a709..f3ca5936 100644
--- a/windows/window.c
+++ b/windows/window.c
@@ -4178,7 +4178,7 @@ static int TranslateKey(UINT message, WPARAM wParam, LPARAM lParam,
         }
 
 
-        /* Nastyness with NUMLock - Shift-NUMLock is left alone though */
+        /* Nastiness with NUMLock - Shift-NUMLock is left alone though */
         if ((funky_type == FUNKY_VT400 ||
              (funky_type <= FUNKY_LINUX && term->app_keypad_keys &&
               !no_applic_k))